Seahorses, those rainbow-hued, color-changing fish that seem to scoot through the ocean, are some of the ocean’s most charismatic creatures. Sadly, a host of factors, from climate change to water pollution, are causing population declines. “Seahorses are especially vulnerable to disturbances,” reports conservation organization Oceana. “They commonly live in seagrass beds, mangroves and coral reefs in coastal shallow waters, which are all highly sensitive [ecosystems].”

While something like the hedgehog seahorse may be the first to come to mind, nearly 50 species of seahorse exist — 14 of which were discovered in just the past decade. In all of these species, the males are the ones that get pregnant and give birth. Seadragons, pipehorses and pipefishes are also members of the Syngnathidae family.

Though we don’t have specific data on many seahorse species, for those we have studied, the outlook doesn’t look good: All but one are vulnerable or threatened, according to the International Union for Conservation of Nature. The two seadragon species are both near threatened, one due indirectly to climate change.

“They are true fish,” he says. They have fins for steering and gills to breathe, though no scales, according to the Monterey Bay Aquarium (MBA). But unlike other fish, they also have a coronet and a snout. “The coronet, the crown-shaped piece of skin on top of its head, is the unique ‘thumbprint’ of each individual seahorse,” notes an MBA factsheet. “The toothless snout of a seahorse is used to slurp up food that it spots with its special eyes.”

Seahorses, which are native to the waters off of 130 different countries, are predators, so they use their large eyes and camouflaging ability — they can change colors and skin texture — to hook onto and blend in with seaweed, Paparo says. “They’re hunting small little fish and shrimp. By holding onto a piece of seaweed and looking like seaweed they can easily hunt down their favorite prey items.” They, themselves, are prey for bigger fish, so the disguise also protects them.

It also makes differentiating between species difficult. “Because of this [camouflaging], some researchers previously thought there were as many as 200 seahorse species in the world, while others thought there were as few as 20,” according to The Smithsonian’s National Museum of Natural History.

Then there are pipehorses, pipefishes and seadragons. Only two true seadragons exist: the weedy and the leafy. “Like seahorses they have chameleon-like eyes, a horse-like head, and a fused jaw. They feed by sucking tiny marine animals such as sea lice and mysid shrimp through these snouts,” according to Project Seahorse. “Unlike seahorses, they swim in a horizontal position and the males do not carry their eggs in pouches, instead using a brood patch under their tails to transport them."

Importantly, there are threats to all these fish, including exploitation for medicine and as souvenirs, Project Seahorse reports. In parts of Asia, for example, seahorses are thought to help treat ailments like asthma, sexual dysfunction and pain, according to Oceana. “The demand for seahorses has exploded in the past few decades, mirroring China’s economic growth.”

Plus, habitat degradation and accidental bycatch in shrimp trawl nets are playing a role, too. Human activity and climate change have severely depleted the places where seahorses thrive. “Seahorses are flagship species, charismatic symbols of the seagrasses, mangroves, coral reefs, estuaries and seaweeds where they make their homes,” Project Seahorse explains. “Protecting seahorses means protecting these diverse habitats all of the marine life that lives therein.”